JPS587183Y2 - Double pipe connection structure - Google Patents

Description

[Detailed description of the invention] This invention is a double pipe used for the purpose of preventing temperature change of the supplied fluid, heating and cooling, etc. in fluid supply piping of chemical plants, etc. It relates to the structure of the connecting part of double pipes used for supply, and in particular, the connection hole that directly communicates the flow path between the outer pipe and the inner pipe of the facing double pipe is connected face-to-face. The present invention relates to the improvement of the structure of a double-pipe connection provided on a flange.

The conventional structure of this type of double pipe connection is, for example, the first
It was as shown in the figure.

In other words, as shown in Figure 1, in the double pipes facing each other,
Flanges 11 for double pipe connection, which are shared by the outer pipe 1 and the inner pipe 2, are provided facing each other at the connecting ends of the double pipes, and between the outer pipe 1 and the inner pipe 2 of the facing double pipes. A fluid connection hole 14 is provided in the portion of each flange 11 located between the inner tube 2 and the outer tube 6 so that the flow paths 6 of the flange 11 can communicate with each other, and a connection hole 14 having the same shape as the connection hole 14 is provided in the portion of each flange 11 located between the inner tube 2 and the outer tube 6. The sealing material 13 in which the hole 14a is formed is inserted between the flanges 110 and the flange 11.
Install it in the same position as the connection hole 14 of the flange 1.
1 with bolts 15 to connect the double pipes.

With such a structure, it is easy to manufacture a double pipe and connect a double pipe joint, and the connection hole 14 of the flange 11 of the casing has a sufficient contact area of the sealing material 13 to the flange 11. If it is provided in a position where it can be used, there is an advantage that the fluid seal at the connection part can be more securely sealed.

However, even with such a flange 11 for double pipe connection, welding may occur due to the pressure difference between the flow path 5 in the inner tube 2 and the flow path 6 between the outer tube 1 and the inner tube 2. For those with a structure, fluid may flow through the double pipe joint into the inner pipe 2 due to welding strain caused by welding the flange joint 11 and the outer pipe 1 and the inner pipe 2, or due to an abnormality in the sealing material 13. Flowing into the connection hole 14 from the passage 5, or flowing into the inner pipe 2 from the connection hole 14.
It may flow into the inner flow path 5 or flow out from the connection hole 14 to the outside of the outer tube 1.

When fluid flows out of the outer tube from the connection hole 14, the outflow can be detected relatively easily visually, but the fluid flows from the flow path 5 to the connection hole 14, or from the connection hole 14 to the flow path 5. It was difficult to detect the inflow.

Therefore, in the present invention, in order to eliminate the above-mentioned conventional drawbacks, at each connecting end of two double pipes facing each other,
A joint flange is provided on the outer pipe and the inner pipe of the double pipe, and the outer pipe and the inner pipe of the double pipe facing each other are provided at the part of the flange located between the outer pipe and the inner pipe. In a double pipe connection structure with a connection hole that directly communicates the flow path between the two pipes, a sealing material is attached to the mating surface of the flange, and a sealing material is attached between the connection hole of the sealing material and the inner pipe. In the part where
An annular or other shaped space is provided, and a fluid outflow hole communicating from this space to the outside of the outer tube is provided in the flange, so that it is possible to detect the phenomenon of fluid inflow between the two flow paths.

Next, details of the present invention will be explained with reference to FIGS. 2.3.4 showing different embodiments.

FIG. 2 shows a case where the joint surface of the flange 11 is one plane.

A sealing material 13 is used on the joint surface of the flange 11, and a space 19 for detecting a fluid inflow phenomenon is provided in the sealing material 13 at an approximately intermediate position between the connection hole 14 and the flow path 5.

Note that 14a is a connection hole for the passage 6 provided in the sealing material 13.

A fluid outflow hole 20 communicating from this space 19 to the outside of the outer tube 1 is provided in the flange 11.

The space 19 may be formed continuously in the circumferential direction in the sealing material 13 and a predetermined number of fluid outflow holes 20 communicating with the space 19 may be provided in the flange 11; In this case, a plurality of sealing members 13 are formed intermittently in the circumferential direction, and are communicated with this space 19 to form fluid outflow holes 2.
0 may be provided on each flange 11.

However, if the continuous space 19 as described above is provided in the sealing material 13, when connecting the flanges, first attach two hollow, concentric sealing materials, one large and one small, to the flange 11 with adhesive or the like. It must be pasted on the joint surface.

The size of the space 19 is set to be as small as possible at the minimum, and furthermore, the space 19 is made of wood or the like at a position approximately midway between the connection hole 14 of the sealing material 13 and the flow path 5. It is necessary to maintain the pressure resistance strength of the material and to satisfy the sealing effect sufficiently.

FIG. 3 shows a case where the joint surface of the flange 11 is step-shaped, and the flange is a fitting type flange consisting of two concentric planes.

Two sheets of sealing material 16 and 17 were used on this joint surface, and a connection hole 14a was provided in the sealing material 17.

The space 19 for detecting a fluid inflow phenomenon is provided continuously on the outer periphery of the sealing material 16 by reducing the outer diameter of the sealing material 16.

A predetermined number of fluid outflow holes 20 communicating with this space 19 were provided in the flange 11.

The space 19 is provided continuously on the inner circumference of the seal 17 by increasing the inner diameter of the seal 17, and the fluid outflow hole 20 communicating with the space 19 is formed in the flange 11.
It may also be provided.

In any case, it is important to select the position where the space 19 is provided so as to maximize the sealing effect of the sealing material in accordance with the shape of the flange joint surface.

FIG. 4 shows a case where the joint surface of the flange 11 is step-shaped and is a fitting type flange consisting of three concentric planes.

Three sheets of sealing material 16, 21, and 17 were used on the joint surface, and the sealing material 17 was provided with a connection hole 14a for the flow path 6.

The space 19 for detecting a fluid inflow phenomenon is provided in an annular shape continuously on the inner circumference of the sealing material 21 by increasing the inner diameter of the sealing material 21.

A predetermined number of fluid outflow holes 20 communicating with this space 19 were provided in the flange 11.

Note that if an outflow detection device or instrument such as a fluid analyzer is connected and attached to the tip of the fluid outflow hole 20 of the flange 11, the inflow phenomenon of fluid between the flow path 5 and the flow path 6 can be reliably detected. Can be detected.

The connection holes 14.14a of the housing are arranged on the same circumference, for example,
It may be possible to arrange four perfectly circular holes, or if the fluid flow rate in the flow path 6 is large, 1. The number of connection holes 14.14a may be increased, or the shape of a housing or elongated hole may be used.

Regarding the installation procedure for inserting the sealing material into the flange 11,
It's best to do it like this:

As shown in Fig. 2, the seal 1 is an integral double-sided seal
3, the position of the connection hole 14a of the sealing material 13 and the connection hole 14 of the flange 11, and the position of the space 19 of the sealing material 13 and the fluid outflow hole 20 are determined by If the holes are defined based on holes, each position can be easily aligned.

Regarding the sealing material of the device shown in Fig. 3, sealing material 1
6 is inserted into the recess 18 of the flange 11, and the sealing material 16 is inserted into the recess 18 of the flange 11.
The space 19 is formed by fixing the sealing material 16 with an adhesive or the like while keeping the gap between the outer peripheral surface of the recess 18 and the inner peripheral surface of the recess 18 substantially constant.

The sealing material 11 is made by defining the position of the connection hole 14j14a based on the outer diameter of the convex part 21 of the flange 11, and by fitting the sealing material 17 into the convex part 21, the flange 1
Make sure to attach it to 1.

Regarding the sealing material of the device shown in FIG. 4, first, install the sealing material 16 by fitting it into the recess 23 of the flange 11 on one side, and then similarly insert the sealing material 21 into the recess 22 of the flange 11 on the other side. Make sure it fits and attaches.

The sealing material 17 is manufactured in the same manner as the sealing material 17 shown in FIG. 3, and is fitted into the convex portion 24 of the flange 11 on one side and attached to the flange.

In this way, in the present invention, as described in the claims for utility model registration, a joint is provided at each connection side end of the double pipe facing each other, which is integrally fixed to the outer pipe and the inner pipe of the double pipe. A connecting hole is provided in the portion of the flange located between the outer tube and the inner tube to directly communicate the flow path between the outer tube and the inner tube of the opposing double tube. In a double pipe connection structure, a sealing material is attached to the mating surfaces of two opposing flanges, and a ring-shaped or other shaped part of the sealing material is located between the connection hole and the inner pipe. Since a space is provided and a fluid outflow hole communicating with the space is provided in the flange, it is possible to reliably detect the outflow of fluid from the flange mating surface and the inflow between the flow channels.

Therefore, invisible internal liquid leaks can be quickly detected and repaired, and safer operation can be achieved.

Furthermore, according to the present invention, it is highly adaptable not only to low-pressure fluid supply piping in chemical plants, etc., but also to medium-pressure and high-pressure fluid supply piping. Measures to manage seals at pipe connections can be easily taken.

[Brief explanation of drawings]

FIG. 1 is a longitudinal nautical chart showing a conventional double pipe connection structure similar to the present invention, and FIGS. 2 to 4 are longitudinal sectional views showing different embodiments of the present invention. 1... Outer pipe, 2... Inner pipe, 5, 6...
...Flow path, 11...Flange, 13.16
．． 17.21... Seal material, 14.14a...
... Connection hole, 19 ... Space, 20 ...
...Fluid outflow hole.

Claims (1)

[Scope of utility model registration request] A joint flange, which is integrally fixed to the outer tube and inner tube of the double tube, is provided at each connection side end of the two double tubes facing each other, and the outer tube of each flange and In a double-pipe connection structure in which a connecting hole is provided in the part located between the inner pipe and the outer pipe and the inner pipe of the double-pipe pipe facing each other to directly communicate with each other, A sealing material is attached to the mating surfaces of the two flanges, and a portion of the sealing material located between the connection hole and the inner pipe is provided with an annular or other shaped space, and from this space A double pipe connection structure characterized by having a fluid outflow hole in the flange that communicates with the outside of the outer pipe.